Cure
by Revhead
Summary: Saving Dean won't be easy. SPOILERS for the season 9 finale, speculation for season 10.


**Cure**

Finding Dean was the easy part.

It took four months, seven tortured demons, six wild goose chases, and one long horrible trail of mutilated bodies, but Sam found him.

He thought he knew what to expect, but it was no less shocking the second time around. The stench of sulphur, the blood coating his hands, the dangerous smirk twisting his lips, the taunting words...and his eyes.

Over the years Sam had seen his brother's eyes twinkling with mischief, brimming with tears, shining with happiness, drooping with exhaustion, burning with rage, broken with despair and empty in death, but they had always been green. Human.

The eyes that stared back at him now were not his brother's. They were the cold, soulless black of a demon.

Seeing what Dean had become, what the Mark of Cain had turned him into, was painful. But it also strengthened Sam's resolve and gave him the grit to pull the trigger.

The iron bullet, engraved with a Devil's Trap the way Henry Winchester had taught them, lodged deep in Dean's skull and prevented him from teleporting or smoking out. The fist fight that followed was brutal – _damn_ Dean was strong now – but just as he was about to deliver the killing blow, Dean hesitated. It was only for a split second, but it was long enough to give Sam the opening he needed to gain the upper hand and knock Dean unconscious.

Sam had then proceeded to cram Dean into the warded trunk of the Impala, drive out to the closest abandoned church, and tightly chain him against an iron Devil's Trap set in the exact centre of one that had been carved into the stone floor. Sam was taking no chances.

But all of that had been child's play compared with what was coming next.

Sam started with his confession. Unlike the "Forgive me, Father" he had done last year as a part of the failed demon trials, he didn't have to dig through 20 years' worth of sins this time around. Unfortunately, admitting to all of the bad things he had done and vowing to do better in the future had not magically transformed him into a good man. In fact, in the year that had passed since his last confession Sam had made exactly the same mistakes. He had declared that his greatest sin was letting Dean down too many times to count, and then what had he done? He had let Dean down _again_.

Sam had been willing to die, to abandon his brother once and for all, when he knew full well that Dean would fall apart without him. Dean couldn't let him go and, because Sam refused to save himself, Dean had turned to an angel for help.

Sam had killed Kevin. Never mind that he had been possessed by an angel and was not in control of his body's actions at the time – he should have fought back the way Dad had when the Yellow-Eyed Demon was torturing Dean, or the way Bobby had when the demon inside him had tried to kill Dean, or the way _he_ had when Lucifer was beating the crap out of his brother and trying to end the world. He should have forced Gadreel out. As much as he wanted to blame Dean for letting the angel in the door in the first place, at the end of the day he had been the one who was too weak to stop Gadreel from using his hands to murder Kevin. That was on him.

When Sam finally did evict Gadreel, he had good reason to be pissed at Dean. But he never should have let Dean walk away. Without his brother at his side, Dean had fallen in with Crowley. He had been led straight to Cain and had taken the Mark because Sam wasn't there to stop him.

Sam had watched as the Mark slowly began to change his brother. For a long time he did nothing, believing that the ends justified the means, and by the time he did try to act it was too late.

But Sam's worst sin was the harsh words he had said to Dean in the name of 'honesty'. Sam had refused to forgive Dean for what happened with the angel even though, in his own misguided way, Dean had thought he was doing the right thing. Sam had said they shouldn't be brothers. He had accused Dean of being needy and selfish, throwing a lifetime of self-sacrifice for Sam's sake back in his face. And then he had taken it one step further, essentially saying that he wouldn't try to save Dean if he was dying. He had not meant it the way it sounded, but he had known how Dean would take it, he had _known_ how much pain it would cause, and he said it anyway.

For months he had made no attempt to bridge the gap between them or to try to fix what had been broken. Dean had hurt him, betrayed him, lied to him, but Sam was the one who destroyed their relationship and declared it to be beyond repair.

When Metatron stabbed Dean, Sam had thought he would never have the chance to make things right. He thought he was going to lose Dean forever. He thought his brother would die believing his family had given up on him.

And then Sam realised that he had lied, to Dean and to himself. Of course he couldn't let Dean die. Of course he would do anything to save him. When push came to shove, Sam was ready to do the same damn thing that Dean had done – make a deal to save his brother.

Only, Dean wasn't dead. He was a demon.

So Sam was going to cure him.

Not as an act of penance, even though he felt guilty for what he had done, but because he loved his brother and he wanted him back.

He was going to do whatever it took.

ooOOoo

"I didn't realise you had a bondage kink, Sammy," Dean drawled, shifting languidly in his chains.

Sam ignored him, moving over to the small table in the corner of the room to retrieve the supplies he would need.

"You gonna torture me, little brother? Get off on the sound of my screams?"

Sam lifted an empty syringe, watching as the needle tip glinted in a thin shaft of moonlight that had struggled through a gap in the boarded-up windows. "No."

"Trust me, dude, an injected dose of holy water works wonders. Even gave Alastair a run for his money."

"This isn't for you. Not yet, anyway." Sam tied a length of rubber tightly around his upper arm and spilled alcohol over his skin to sterilise it. Then he popped the safety cap off the syringe and slid the needle into a vein. Slowly, slowly, the syringe filled with blood.

"Hell, I could give you the whole torture tutorial if you'd like," Dean continued. "I was mostly playing from the demon handbook last time, but lemme tell ya, once you start using your imagination and experimenting a little there is a whole new world of pain to discover. With what I know now, I bet I could pull a scream from a corpse. Want me to teach you?"

"No, thanks." Sam withdrew the needle and undid the tourniquet before approaching the creature that had been his brother and would be again.

The teasing lilt dropped from Dean's voice. "What the hell do you think you are going to do with that?"

"I'm going to fix you."

"Fix me? Sammy, I feel good! Better than I ever have."

Sam stared into black eyes. "You're a demon," he said flatly.

"Yeah. I'm stronger, faster. I don't have to eat, or sleep, I don't get tired. To my eyes, the whole world is in high definition. I can hear heartbeats, I can smell fear and I can sense a human soul from a mile away. And the power…" He rolled his eyes rapturously. "Oh, Sammy, it is all power all the time. What's not to love?"

"This isn't what you wanted, Dean. You would have rather died than turn into this."

"That was before I knew what it was like. It is a rush that you never come down from."

"You're coming down, Dean. I'm going to make sure of it."

With that, Sam stabbed the needle into Dean's neck and depressed the plunger.

ooOOoo

When Sam returned an hour later, Dean's features twisted with hatred at the sight of him before he dragged his expression back under control.

"Sammy. Back for our second date? For a few minutes there I was worried that you would stand me up." His words were casual, but his tone was underlined with barely repressed rage.

Sam didn't respond, silently preparing the second needle.

"I gotta tell ya, Sammy, last time didn't really do it for me, you know? So I'm thinking we should change it up. You put away your little stick and I'll give you some of _my_ blood instead."

Sam stiffened.

"You'd like that, wouldn't you, Sammy? You remember how good it felt when you were sucking on Ruby? She was demon _filth_ compared to me. I'm a Knight of Hell, Sam. Imagine how good I'll taste. Imagine the power I could give you. You could slice me open and feel my blood spill across your hands, then drink me down, deeper and deeper until my power sang within your veins. You could be strong again. Unstoppable."

Sam determinedly stilled the tremble in his hands. He had kicked the habit years ago and he wasn't about to start drinking demon blood again now. "I think I'll pass."

A growl built deep in Dean's throat as Sam approached with the second dose. "Don't _touch_ me!"

Sam grabbed a fistful of Dean's hair and yanked his head to the side, baring his throat to the press of the needle.

"Sorry, man. You'll thank me for this when it's done."

"You son of a _bitch_!" Dean spat as soon as Sam released him.

"Don't talk about our mom that way," Sam chided.

Ignoring the yells of profanity from behind him, Sam took his leave of the church. He drew in a deep breath of the cool night air and it steadied him. He could do this.

ooOOoo

When Sam came back to prepare the third dose, Dean had lost any pretence of calm. He snarled at Sam with all the ferocity of a cornered animal, twisting and writhing against the chains that held him. His wrists were bleeding, he was soaked in sweat and his eyes were wild.

"This is for your own good, Dean."

Dean gnashed his teeth, hissing and spitting and snarling. As soon as Sam was close enough he threw himself forward, trying to rip a chunk of flesh out of Sam's arm. Wise to this trick from his experience with Crowley, Sam punched Dean in the face hard enough to daze him and quickly injected the blood into Dean's veins before he had the chance to recover.

ooOOoo

Dean shrank away from him in fear when Sam came over to deliver the fourth injection.

"No. _No." _He shook his head frantically, pressing back up against the Devil's Trap that held him, trying to get as far away from Sam as he could. "Don't, Sammy, don't do this to me! Kill me, torture me, send me to Hell – anything but this. Please, I'm begging you."

Sam tried not to show how his brother's words were affecting him. Dean didn't beg. He wouldn't beg, not unless things were really, really bad. "Dean, we are half way there. In a few hours this will be over. You will be you again."

Dean let out a howl of misery as the blood hissed into his veins.

The look he gave Sam was one of pure betrayal. "How could you do this to me, Sammy?"

ooOOoo

The fifth time Sam entered the church, Dean was eerily quiet.

Slumped in his chains, eyes downcast to the floor, Dean looked exhausted. He didn't even look up at the sound of footsteps coming towards him or at the slight spatter of blood when Sam squirted the air out of the needle.

"Don't do this," Dean whispered.

Sam paused, disconcerted to hear the quiet desperation in his brother's voice.

"Dean…"

"You don't know what it will do to me."

"Yes I do, Dean. It will give you back your humanity."

Dean huffed a quiet, mirthless laugh. "Humanity. You say that like it is a good thing."

"It is."

"No, Sammy. I know what it means to be human. I was one not so long ago, and I remember. It was pain. Grief. Heartache. Fear. Loneliness. Worthlessness. Guilt. Despair."

Sam frowned. "It's not all bad."

Green eyes flicked up to look at him. Even without the pollution of black, they were empty. Lifeless. "I was barely keeping it together, man. I don't want to go back to that."

Sam felt a pang, deep in his chest. "It will be okay, Dean. I promise."

Dean just shook his head, wordlessly.

He didn't bother to fight when Sam slid the needle into his neck.

ooOOoo

"Why are you doing this, Sam?" Dean's voice was weary and his glazed eyes barely managed to focus on Sam's face.

"You know why."

Slowly, Dean shook his head. "No. I don't."

"I'm trying to save you."

Dean stared at him, numb disbelief written all over his features. "Why?" he asked hoarsely. "You said you wouldn't."

A familiar frustration bubbled up within him. "I meant I wouldn't let an angel possess you without your consent, Dean. I wouldn't violate your free will, or your body, like that."

Dean looked away, ashamed. "I'm sorry, Sam. I didn't mean… I didn't…"

Sam sighed. "I know."

Hesitantly, Dean glanced back up at him. "But what you're doing now… isn't it the same? You know this isn't what I want."

"The demon part of you doesn't want it, just like I didn't want my soul back when it was trapped in the Pit. But when you were human, Dean, turning into a demon was your worst nightmare. You didn't want to live like this. I'm honouring your wishes."

"Sammy… I wanted to die. I didn't want you to save me."

Sam didn't know what to do with that. He remembered Dean saying it was better this way shortly before he died in Sam's arms. But it wasn't better. It _hurt._ Dean was gone and Sam was alone and he couldn't bear it, especially not with the way they had left things between them.

He refused to believe that Dean had wanted to die. He might have wanted peace, happiness, freedom – but not death. Just like Sam hadn't wanted to die, not really. He just hadn't wanted to keep living the way they were living.

"Well, too bad. This will make us even. And then we can be okay. We can be brothers again."

Dean looked at him, not quite believing. "Is that really what you want?"

"Yeah," Sam tried to say, but his voice broke. How had they let their relationship become so damaged? They were supposed to be family. "Yeah, that's what I want. I miss you, Dean."

Dean stared at him for a long moment. Then slowly, he tilted his head, giving Sam's needle access to his neck.

ooOOoo

"You know, Sammy, I still don't get it."

Sam glanced over from the table, beginning to feel slightly lightheaded from the blood loss but nowhere near as bad as he had felt when he had been doing the demon trials.

"What?"

"Why you're doing this. What… what is so worth saving?"

"You," Sam replied simply.

"But I know who I am. I was messed up even before Cain gave me his Mark, Sammy. I've been messed up since Mom died and over the years I've just gotten worse and worse. I have this _hole_ inside me and I tried to fill it with women and hunting and sarcastic humour, but instead it got crammed full of death and loss and heartache and torture and now I am just a twisted mass of darkness and bloodlust and self-loathing and – and _evil_."

"You're not evil."

"I've killed people, Sam. Innocent people. If Dean Winchester was ever a good man he is long gone and I don't think… I don't think I will ever be able to find him again."

"Yes you will. I believe in you, Dean."

Dean's eyes welled up with tears. "How can you, after everything I've done? I've lied to you, abandoned you, dragged you into harm's way, stolen every chance you ever had at happiness, bossed you around, treated you like a freakin' child, gotten you killed, dragged you back to life, driven you away, called you a freak and a monster, left you rotting in Hell, broken you down and torn you apart, and I let an angel date-rape you. I practically held you down for him. I'm the reason you're not at peace in your own private Heaven right now, I'm the reason you have nightmares about killing Kevin. After all the crap you have been through because of me, why would you try to cure me? You have every excuse to shoot me full of rock salt and chop me into pieces too small to find, so why? I don't understand, Sammy. I don't know why you would want me back."

All of those things had hurt, it was true. But Dean couldn't shoulder all of the blame for everything that had ever gone wrong between them. Sam was just as guilty of hurting his brother. Somehow they had to stop this vicious cycle and find their way back to being family.

"We've both said and done things to be ashamed of, Dean. But you said it yourself – you're proud of us. Because through all of the crap, we've stuck together and we have done a hell of a lot of good in this world. We have always tried to do the right thing and we have saved so many people. But more important than any of that is how we pick ourselves up and keep going, keep fighting the good fight, keep trying to do better. I'm proud of us, too, Dean."

A single tear slipped down Dean's cheek.

Sam wiped it away gently with his thumb, then held up the syringe. "C'mon, big brother," he said softly, "we're nearly there."

Dean let Sam give him the seventh injection.

One more to go.

ooOOoo

Dean was shifting restlessly as Sam prepared the final needle.

"S-sammy?"

"Yeah, Dean."

Dean swallowed. Sam could have sworn there was fear in his eyes. "I- I have a bad feeling about this."

"Everything is going to be alright, Dean. Don't worry."

"But… this thing inside me. I don't think… I don't know…"

Sam kept his voice low and reassuring. "Trust me, Dean. It will be okay."

Dean nodded feverishly. "I do trust you. I trust you."

"Okay, then. Let's do this."

Dean swallowed and shrank back a bit, but he didn't fight or struggle as the last dose of blood seeped into his veins.

Sam closed his eyes briefly, hoping to high heaven that what he was about to do would work. Then he began to speak the words of Father Thompson's ritual. "_Exorcizamus te, omnis immundus spiritus. Hanc animam redintegra, lustra_!"

Dean jerked in his chains. His eyes flashed to an intense black.

Sam drew a knife through his hand, spilling fresh blood. He pressed the hand over Dean's mouth and shouted the last word: "_Lustra_!"

Dean _screamed_.

There was a blinding flash of white light.

When the light faded, the black was gone from Dean's eyes. He dragged in a huge gasp of air, flailing with panic before he caught sight of his brother.

"Sam? Sammy?"

Sam offered a tremulous smile. "I'm right here, Dean."

"Did – did it work?"

"Yeah."

Dean nodded, relief swamping his features. "It's over, then."

"Yeah. Let's get you out of those chains, huh?"

"Please," Dean sighed.

Sam unlocked the manacles as quickly as he could. Dean began to crumple but Sam pulled his brother into his arms. "Hey, hey, it's okay, I've got you."

"Thanks, Sam," Dean whispered.

Sam tightened his grip, ducking his head into Dean's shoulder, barely holding back his tears. "God, Dean, I missed you."

But instead of responding, Dean jerked back with a startled cry.

"What? What is it? Dean!"

Dean doubled over, arms folding across his middle. "Sam-" he choked. He dropped heavily to his knees.

"Dean, what's wrong?"

Dean lurched forward and made a horrid retching sound. He had not eaten in four months so there was nothing for him to bring up, but after a few hacking coughs he began spitting out blood. A lot of blood.

Sam grabbed Dean by the shoulders, alarmed, panicking, trying to offer support when he had no idea what was happening. "Dean, hang in there. It's okay-"

Then he saw it.

The Mark of Cain, burning red and angry on Dean's forearm.

The ritual had restored Dean's humanity, but the Mark was still there.

"Dean-"

"Crowley warned me," Dean coughed. More blood splattered the floor. "He said – my body – can't handle – the Mark – if I'm human."

Sam's mind whirled. He remembered seeing the bloodied vomit in Dean's cell after Dean had broken out and stolen the Blade, but he hadn't realised that his brother was dying.

"It's killing you?"

Dean managed a slight nod before he keeled over again with a wretched groan, his body going into spasms as he choked up more blood.

"That is- unless – Metatron does me in first…"

Sam spun around, expecting to see the would-be-god behind him, but there was no one there. "Metatron's locked up in Heaven, Dean, he can't hurt you."

Dean shook his head. "He – already – did." His hand fluttered weakly to his chest.

Blood was staining his shirt, spreading in a dark pool of crimson.

Dean had been stabbed with an angel blade.

"Demons – don't heal," Dean gasped out. "I've been – a dead man – walking. Guess – my time's up – huh, Sammy?"

"No!" Not again. Not again. Not like this. Not when they were just starting to be brothers again. Not when he had gone to all this effort to save him. "No, Dean-"

"Sorry, Sammy. But… thank you."

Sam couldn't see for the tears blurring his eyes. He was losing Dean again. He couldn't do this. He couldn't. "For what?"

"For saving me," Dean exhaled, giving his brother the faintest smile.

Then he slumped forward.

Sam caught him, pulling him into a desperate hug. "No, no, no, no, no. No, please, Dean, please…"

"Sorry…" Dean whispered. His body went limp.

"No!" Sam yelled. "_CAS!"_

There was a flutter of wings.

"_Heal him_," Sam screamed. "Fix him! Don't let him die!"

Cas took in the scene before him in an instant and strode forward to take Dean from Sam's arms. He quickly laid him out on the floor, examining his injuries.

"Sam, I don't know if my Grace is strong enough to-"

"_DO IT!_"

Cas pressed his palm against Dean's forehead.

Light oozed from his wounds as they closed over. Castiel's face twisted with pain.

Dean's chest rose and fell. Once. Then again, sluggishly. His breathing slowly began to pick up a normal rhythm, but then Dean let out an agonised groan, curling in on himself, the Mark burning stronger than ever.

"I have healed his injuries, but what the Mark is doing to him may be beyond my ability to-"

Sam grasped desperately at Castiel's trench coat. "_Please._"

Castiel's face was sombre. "I can only try."

He removed his hand from Dean's forehead, then slowly turned his wrist so the Mark faced upwards.

"I don't know what this will do," he warned. When Sam made no move to stop him, Cas drew in a careful breath, and gently placed his hand over the Mark. He closed his eyes, brow furrowing with pain and concentration.

Then he screamed, and Dean screamed, and there was a burst of light so intense that Sam recoiled as he reflexively slammed his eyelids shut.

When he dared to open his eyes, Cas and Dean were both lying unconscious on the floor.

Dean's arm was still seared with a mark.

But it wasn't the Mark of Cain.

It was a handprint.

"Guys? Dean, Cas? Wake up. Come on. Be okay. Please be okay."

Sam shook them both in turn, becoming more and more frantic until Cas groaned and Dean opened his eyes.

"What- what happened?"

"How do you feel?" Sam asked urgently.

"Fine- I- Cas?"

Cas was slowly pushing himself upright. Every movement looked like it hurt.

Dean sat up, too, giving his friend a quick once-over as he searched for injuries. "Buddy, you okay?"

Cas just looked at the burned flesh of Dean's arm, drawing Dean's gaze to it as well.

"What did you do?"

"Your soul was branded by Hell," Cas explained wearily. "I claimed it back. But in doing so, I burned away the last remnant of my Grace."

Dean's face clouded with worry. "Are you dying?"

"No. Miraculously, the touch of your soul restored me to health. I am simply…"

"Human," Sam filled in.

Cas nodded.

Dean clapped the ex-angel on the shoulder and pulled him to his feet. "Well, that makes two of us."

"Three," Sam corrected.

"You're right," Dean grinned. "Team Free Will, together again. And you know what? I think we three are enough."

"We always have been," Cas said.

Sam pulled them both into a rough hug. "I love you guys."


End file.
